For me, the ability to create custom bangs is worth it alone. I probably have close to a hundred bangs now and even created a bang to edit my bangs. I’m sure there are extensions that can replicate this behaviour but Kagi works on any device without any prior setup. My ‘site:reddit.com’ (!r) bang has to be my favourite, although I have found myself needing it less with Kagi since I’m already able to preference Reddit in search results.